Tuesday, April 10, 2007

Bus vs. driving

One of the things I really miss about Boston is the great public transportation. When I lived there, I would take the T everywhere. Always the subway, though - I've never been a bus person.

Lately, though, I've been riding the bus to work on days when I can (namely, if I don't need to drive somewhere mid-day, or if I can leave work in time to catch the last bus home). It's actually quite nice to do - there's a park-and-ride near my house, and an express bus that goes from the P&R to a stop that is one block away from work with only a single stop in between and no transfers.

When I take the bus, I leave the house at 7:30am, get to the P&R at 7:36, catch the bus at 7:39, and am at my office by approximately 8:08, 38 minutes door to door. Since the bus travels in the carpool lane, there is very little variability day-to-day in drive-time.

When I drive, I leave the house at the same time but go a more direct route. Inevitably, as a single-occupancy car, I get caught at the metered on-ramp to the highway and in traffic once I'm on the highway, but even with that, I am generally in the garage at work by 8, and in my office shortly thereafter. There is, of course, more variability in my drive time, but surprisingly driving is actually almost always about 5 minutes faster door-to-door, even accounting for typical mid-week traffic. (Of course, on some days the traffic is really bad, and it can take me close to an hour to drive home.)

I pay $3 for the round trip on the bus. I probably burn a gallon and a half of gas for the round trip in the car, so call it $4.50 to drive, so on days that I take the bus I'm saving a bit of pocket change and save the planet a little bit from the gas I don't burn.

I also pay $100/month for parking in my building because I need to drive 40-60% of days for one reason or another. That works out to about $5/workday, or about $10 on average for my driving days. Since parking for the day a-la-carte would be about $10/day, I break even on parking if I drive about half the days, which I do. Of course, since I can't ride the bus every day, I have to pay this regardless of whether I drive or ride the bus.

So economically, if I drive half of my workdays, I'm effectively paying $4.50 of marginal costs for my commute, vs. $3 for days when I ride the bus. (Yeah, yeah, there are lots of fixed costs associated with driving, but I'd be paying them regardless of whether or not I drive or take the bus, so it's not appropriate to include them in the comparison.)

So all in all, it's a pretty good deal for the bus: I save ~$1.50/day that I ride, I remove a car from the road for the day, and (most importantly) I can read or catch up on work while someone else drives. Obviously, if I ride the bus more, then my per day parking rate goes way up, if I ride the bus less, my per-day parking goes down.

The downsides? Only two, really: it's obviously way less flexible than driving (I can't ride the bus if I can't leave work promptly at 5ish or else I'll have a long commute with transfers to get home, I can't stop to pick up dinner or groceries, etc.), and it's a bit slower door-to-door than driving, even with traffic.

Of course, the fact that this is almost point-to-point for me helps a lot; for many people, taking the bus involves transfers and a significant walk. That, I think, is the key problem with public transportation: people won't use it without a critical mass of saturation/density is important.

So I'm a convert. Now I just wish they'd build a subway system out here, or something that would make it much easier and faster to get from where I live into and out of Seattle.

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